1. Field of the Invention
The present invention generally relates to an inertia-sensing technology and, more particularly, to a real-time motion recognition method and an inertia-sensing and trajectory-reconstruction device using inertia-sensing signals to perform change-point detection and trajectory reconstruction recognition.
2. Description of the Prior Art
With the advancement in technology, the modern life is closely connected with information technology products. Among them, computers and handsets are especially used in the daily life. The user uses these computers technology products to send commands to the computer to show results on the display after the commands have been processed and/or transferred. In such a process, an input interface is required for communicating the user and the computer.
The keyboard and the mouse are the most popular user interfaces. Generally, the mouse is function-limited and cannot process complicated instructions, while the keyboard requires a time-consuming training process. Moreover, it is difficult or time-consuming to realize delicate drawing and processing by using the keyboard or the mouse. Therefore, other input schemes such as handwriting and voice have been developed. On the other hand, with the rapid development in multi-media technology, the technology of the user interface interacted with the multi-media has launched. Generally, the user interface interacted with the multi-media uses a sensor capable of detecting the acceleration or the angular velocity. The development in the technology of determining the start and the end of the sensor has been intensively reported.
The conventional handwriting technology specialized in motion identification can be divided into several categories. Firstly, in U.S. Pat. No. 5,902,968, a handwriting device using button-free sensing is disclosed, wherein accelerometers and gyroscopes are used to detect a state of handwriting or non-handwriting. The handwriting device compensates for the effects of the inclination angle of a pen shaft when writing so as to obtain the movement distance. Whether the device is in motion is determined based on whether the signals of the accelerometers and gyroscopes are above 10 Hz. If the signals are above 10 Hz, the handwriting device is in a handwriting state and compensates for the effects of the inclination angle of a pen shaft when writing so as to obtain the movement distance. Moreover, in U.S. Pat. Pub. No. 2004/0184659, a handwriting trajectory recognition system and method are disclosed. The handwriting trajectory recognition system comprises: a motion detection unit adapted to output electric signals based on changes in acceleration of a body of the system in space and a control unit adapted to detect non-stroke regions intervals where the motions of the system body are temporarily stopped and recover handwritings based on the electric signals.
Secondly, in U.S. Pat. Pub. No. 2002/0067350, a wireless handwriting device using button-type sensing is disclosed. When the user pushes a button to start wireless transmission so that the processor compares the acceleration parameters from accelerometer with a stored acceleration sequence to perform recognition and then a Blue-Tooth transmitter transmits information to the terminator. Whether the device is in writing state is determined based on whether the user pushes the button to perform recognition.
Thirdly, in U.S. Pat. Pub. No. 2006/0088215, a handwriting recognition system using a pressure gauge to detect and determine whether the system is in motion is disclosed. A pressure gauge is disposed at the front of the handwriting recognition system to determine whether the handwriting recognition system contacts the handwriting surface and separate trajectory signals and non-writing signals. The handwriting trajectory is then calculated based on the acceleration and the change-point of the handwriting signal is detected according to the pressure gauge. Moreover, in U.S. Pat. No. 6,628,847, a pressure gauge is disposed on the stylus to determine whether the handwriting recognition system contacts the handwriting surface and separate trajectory signals and non-writing signals.
Fourthly, in U.S. Pat. No. 5,923,793, a handwriting device is disclosed, wherein whether the stylus contacts a handwriting plate determines whether the handwriting device is in a handwriting or non-handwriting state. When the user writes on the handwriting plate, the handwriting device determines the position of the stylus in a specific region and the handwriting characteristics are stored in a memory for recognition. Since the stylus contacts the handwriting plate to determine the start point of handwriting, only 2-D handwriting can be identified. Moreover, U.S. Pat. Pub. No. 2007/0038711 also discloses a handwriting and recognition device for 2-D handwriting.